Rotary shaft for a piece of seating furniture

ABSTRACT

Rotary shaft for an item of seating furniture, comprising a rotary spindle rotatably guided in a rotary sleeve, wherein the rotary spindle comprises a radial groove into which a pin radially protrudes from the rotary sleeve, wherein the groove is formed to be not completely circumferential.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the priority benefits of International Patent Application No. PCT/EP2014/071170, filed on Oct. 2, 2014, which claims priority of DE 20 2013 105 028.8, filed on Nov. 8, 2013, which are hereby incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

The invention relates to a rotary shaft of an item of seating furniture having a corresponding rotary shaft.

It is generally known to configure swivel chairs, such as office chairs, such that the seating surface thereof can be rotated in a full circle relative to the base. For instance, DE 1903637U discloses a corresponding swivel chair.

However, it is not always desirable for the seating surface to be able to rotate relative to the base by 360 degrees, i.e. without a stop, because e.g. cables for supplying electrical power to, or controlling, e.g. massage functions would otherwise become wound up.

SUMMARY OF THE INVENTION

Therefore, on the one hand, chairs exist which comprise a stop which consists of a protruding pin attached to the lower side of the seating surface and of a stop element arranged on the rotary shaft. However, in this case it is a problem that the stop is located far outside the rotary shaft and is thus subjected to relatively large forces. This can lead to the stop being destroyed and also to undesired movement of the base owing to the forces being absorbed upon impact.

Furthermore, swivel chairs are known in which complete rotation is not possible because the rotary shaft, upon rotation, is offset in height by means of angular surfaces which act opposite each other, and therefore the seating surface returns to the initial position under no-load conditions. However, the height offset and also the automatic position return are undesired.

The invention provides an option by means of which rotation of the seating surface is provided but this can be limited, and a height offset does not occur.

A rotary shaft for an item of seating furniture, according to an aspect of the invention, includes a rotary spindle that is rotatably guided in a rotary sleeve. The rotary spindle includes a radial groove into which a pin radially protrudes from the rotary sleeve. The groove is formed to be not completely circumferential.

In accordance with this aspect of the invention, it has been recognized that when the rotary shaft comprises a rotary spindle having a radial groove into which a pin radially protrudes from the rotary sleeve, wherein the groove is not formed to be completely circumferential, a stop, close to the shaft, against a complete circular rotation can be created in a simple manner. Therefore, on the one hand, the exerted forces can be controlled and, on the other hand, a visually appealing solution is provided.

The groove which is not completely circumferential is thus in other words a non-circumferential annular groove in the peripheral surface of the rotary spindle. The thus non-grooved region or the remaining web (thus defines two end sides of the groove) is used as a stop for the pin protruding into the groove.

The groove which is not completely circumferential can be provided with cushioning stops at the end sides of the groove. Therefore, the impact of the pin is cushioned which provides user comfort and the material is not damaged. The cushioning stops can consist of elastomer inserts. These can be inserted into a receptacle provided between the end sides of the groove and connecting same. They can be designed in one piece and held in a clamping manner. The elastomer inserts may have a quasi-double-T shape.

Furthermore, friction-reducing inserts can be provided between the rotary sleeve and the rotary spindle. The groove, which is not completely circumferential, of the metallic rotary spindle may be milled from the solid material.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and details of the invention shall be apparent from the following description of the drawing, in which:

FIG. 1 shows a schematic side view of a rotary shaft assembly;

FIG. 2 shows a section along line A-A of FIG. 1;

FIG. 3 shows a schematic side view of the rotary spindle of FIG. 1; and

FIG. 4 shows a further schematic side view of the rotary spindle of FIG. 1 in a different position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The figures illustrate an item of seating furniture, such as a swivel chair or reclining chair, having a seat, a base and a rotary shaft assembly, designated as a whole with numeral 1, of the chair. The rotary shaft assembly has a rotary spindle 3 rotatably guided in a rotary sleeve 2. The rotary spindle 3 comprises a radial groove 4 into which a threaded pin 5 protrudes radially from the rotary sleeve 2.

The groove 4 which is not completely circumferential is an “annular groove” which is not completely circumferential in the peripheral surface of the rotary spindle 3. The non-grooved region or remaining web 6 (cf. FIGS. 3 and 4) thus defines two end sides 7A, B of the groove and is used as a stop for the pin 5 protruding into the groove.

The groove 4 which is not completely circumferential comprises cushioning stops, at the end sides 7A, B, in the form of glued-in elastomer inserts 8.

Furthermore, friction-reducing inserts 9, 10 are provided between the rotary sleeve and the rotary spindle in the upper and lower regions of the rotary sleeve 2.

The upper insert 9 and a snap-ring 11 on the lower side of the rotary spindle 3 hold same in the sleeve 2. 

1. Rotary shaft for an item of seating furniture, comprising: a rotary spindle rotatably guided in a rotary sleeve, wherein the rotary spindle comprises a radial groove, a pin radially protrudes from the rotary sleeve into the groove, wherein the groove is formed to be not completely circumferential.
 2. The rotary shaft as claimed in claim 1, including cushioning stops at end sides of the groove.
 3. The rotary shaft as claimed in claim 2, wherein the cushioning stops comprise elastomer inserts.
 4. The rotary shaft as claimed in claim 2, including a receptacle connecting the end sides between the end sides of the groove.
 5. The rotary shaft as claimed in claim 1, including friction-reducing inserts between the rotary sleeve and the rotary spindle.
 6. The rotary shaft as claimed in claim 1, wherein the groove of the metallic rotary spindle is milled from the solid material.
 7. An item of seating furniture, comprising: a seating surface, a base and a rotary shaft between said base and said seating surface; said rotary shaft including a rotary spindle rotatably guided in a rotary sleeve, wherein the rotary spindle includes a radial groove, a pin radially protrudes from the rotary sleeve into the groove, wherein the groove is formed to be not completely circumferential.
 8. The item of seating furniture as claimed in claim 7 comprising a swivel chair or reclining chair.
 9. The item of seating furniture as claimed in claim 7, including cushioning stops at the end sides of the groove.
 10. The item of seating furniture as claimed in claim 9, wherein the cushioning stops comprise elastomer inserts.
 11. The item of seating furniture as claimed in claim 9, including a receptacle connecting the end sides between the end sides of the groove.
 12. The item of seating furniture as claimed in claim 7, including friction-reducing inserts between the rotary sleeve and the rotary spindle.
 13. The item of seating furniture as claimed in claim 7, wherein the groove of the metallic rotary spindle is milled from the solid material.
 14. The item of seating furniture as claimed in claim 10, including a receptacle connecting the end sides between the end sides of the groove.
 15. The item of seating furniture as claimed in claim 9, including friction-reducing inserts between the rotary sleeve and the rotary spindle.
 16. The item of seating furniture as claimed in claim 9, wherein the groove of the metallic rotary spindle is milled from the solid material.
 17. The rotary shaft as claimed in claim 3, including a receptacle connecting the end sides between the end sides of the groove.
 18. The rotary shaft as claimed in claim 2, including friction-reducing inserts between the rotary sleeve and the rotary spindle.
 19. The rotary shaft as claimed in claim 2, wherein the groove of the metallic rotary spindle is milled from the solid material. 